The
Common Brushtail Possum (
Trichosurus vulpecula, from the
GreekAncient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
for "furry tailed" and the
LatinLatin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
for "little fox", also known as
Phalangista vulpina) is a nocturnal, semi-arboreal
marsupialMarsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...
of the family
PhalangeridaePhalangeridae is a family of nocturnal marsupials native to Australia and New Guinea, including the cuscuses, brushtail possums, and their close relatives...
, it is native to
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, and the largest of the
possumA possum is any of about 70 small to medium-sized arboreal marsupial species native to Australia, New Guinea, and Sulawesi .Possums are quadrupedal diprotodont marsupials with long tails...
s.
Like most possums, the Common Brushtail is nocturnal. It is mainly a
folivoreIn zoology, a folivore is a herbivore that specializes in eating leaves. Mature leaves contain a high proportion of hard-to-digest cellulose, less energy than other types of foods, and often toxic compounds. For this reason folivorous animals tend to have long digestive tracts and slow metabolisms....
, but has been known to eat small mammals such as rats. In most Australian habitats, leaves of eucalyptus are a significant part of the diet but rarely the sole item eaten. The tail is
prehensileA prehensile tail is the tail of an animal that has adapted to be able to grasp and/or hold objects. Fully prehensile tails can be used to hold and manipulate objects, and in particular to aid arboreal creatures in finding and eating food in the trees...
and naked on its lower underside. There are four colour variations: silver-grey, brown, black and gold.
It is the
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n
marsupialMarsupials are an infraclass of mammals, characterized by giving birth to relatively undeveloped young. Close to 70% of the 334 extant species occur in Australia, New Guinea, and nearby islands, with the remaining 100 found in the Americas, primarily in South America, but with thirteen in Central...
most often seen by city-dwellers, as it is one of few that thrive in cities, as well as a wide range of natural and human-modified environments. Around human habitations, Common Brushtails are inventive and determined foragers with a liking for fruit trees, vegetable gardens, and kitchen raids.
In
New ZealandNew Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, where it was introduced in the 19th century, it is a major agricultural and conservation pest.
Description
The common brushtail possum has large and pointed ears. It has a bushy tail (hence its name) with a prehensile tip and a hairless patch on the underside which helps it grasp tree branches. Its forefeet have sharp claws and the hindfeet each have an opposable, clawless toe which have good grips. The second and third toes are fused with a long, split claw that is used for grooming. The brushtail possum has thick and woolly fur that ranges in colour depending on the subspecies. Colour patterns tend to be silver-gray, brown, black, red or cream. They tend to have lighter underbellies and brown or black tails. It also has and dark patches on its muzzle. The common brushtail possum has a head and body length of 32-58 cm with a tail length of 24-40 cm. It weighs 1.2-4.5 kg. Males are generally larger than females. In addition, the coat of the male tends to blend into reddish at the shoulders. As with all marsupials, the female brushtail possum has a forward-opening, well-developed pouch. The brushtail possum has a scent gland located on the chest used to mark territories. The reddish secretions from this gland give the fur around it a brown or reddish appearance.
Range and habitat
The common brushtail possum is perhaps most widespread mammal of Australia. It is found throughout the eastern and northern parts of the continent, as well as some western regions, Tasmania and a number of offshore islands, such as
Kangaroo IslandKangaroo Island is Australia's third-largest island after Tasmania and Melville Island. It is southwest of Adelaide at the entrance of Gulf St Vincent. Its closest point to the mainland is off Cape Jervis, on the tip of the Fleurieu Peninsula in the state of South Australia. The island is long...
and
Barrow IslandBarrow Island is the name of at least three islands:*Barrow Island *Barrow Island, Cumbria, England*Barrow Island...
. It is also widespread in New Zealand since its introduction in 1840. The brushtail possum can be found in a variety of habitats, such as rainforests, woodland, dry eucalypt forest, pine plantations, semiarid areas and even parks and gardens in urban areas. It is mostly a forest inhabiting species, however it is also found in treeless areas. In New Zealand, the highest population densities (5-25 per ha) appear to occur in broadleaf-podocarp forests that have a rich understory of nutritious species or are adjacent to farmland pastures. Much lower densities (1-3/ha) occur in
southern beechNothofagus, also known as the southern beeches, is a genus of 35 species of trees and shrubs native to the temperate oceanic to tropical Southern Hemisphere in southern South America and Australasia...
forests and pine plantations that lack understory species. In Australia, most densities are less than 2/ha, ranging from less than 0.3/ha to a maximum of 6/ha in a Tasmanian rainforest. These lower densities in their native land are likely due to sparser vegetation forests in eucalypt forests, as well as the existence of predators that do not exist in New Zealand. In Australia, brushtail possums are threatened by humans,
tiger quollThe tiger quoll , also known as the spotted-tail quoll, the spotted quoll, the spotted-tailed dasyure or the tiger cat, is a carnivorous marsupial of the quoll genus Dasyurus native to Australia...
s,
foxFox is a common name for many species of omnivorous mammals belonging to the Canidae family. Foxes are small to medium-sized canids , characterized by possessing a long narrow snout, and a bushy tail .Members of about 37 species are referred to as foxes, of which only 12 species actually belong to...
es,
catThe cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s,
goannaGoanna is the name used to refer to any number of Australian monitor lizards of the genus Varanus, as well as to certain species from Southeast Asia.There are around 30 species of goanna, 25 of which are found in Australia...
s, carpet snakes and certain
owlOwls are a group of birds that belong to the order Strigiformes, constituting 200 bird of prey species. Most are solitary and nocturnal, with some exceptions . Owls hunt mostly small mammals, insects, and other birds, although a few species specialize in hunting fish...
s. In New Zealand, brushtail possums are threatened only by humans and cats.
Food and foraging
The common brushtail possum thrives on whatever vegetation is available. It eats
EucalyptusEucalyptus is a diverse genus of flowering trees in the myrtle family, Myrtaceae. Members of the genus dominate the tree flora of Australia...
leaves. However, it will also eat flowers, shoots, fruits and seeds. Brushtail possums have adapted to eating several introduced species, such as the shoots and male cones of pine trees in plantations, pastures of clover and grass. In suburban gardens, they will eat ornamental and orchard species. They will also eat animal matter, such as insects, bird eggs and sometimes other small animals, including young birds. In New Zealand, brushtail possums have colonised all the native forests and eat many of the broad-leafed tree species, particularly the several species of
rataRata may refer to:* Plants of the genus Metrosideros from New Zealand, including** Metrosideros robusta ** Metrosideros bartlettii ** Metrosideros carminea...
and pohutakawa of the genus Meterosideros, which is a distant relative of eucalyptus. In both Australia and New Zealand, brushtail possums may eat three or four different plant species in a night of foraging, unlike some other tree-dwelling marsupials, such as the
koalaThe koala is an arboreal herbivorous marsupial native to Australia, and the only extant representative of the family Phascolarctidae....
and the
greater gliderThe Greater Glider is a small gliding marsupial found in Australia. It is not closely related to the Petaurus group of gliding marsupials but instead to the Lemur-like Ringtail Possum , with which it shares the subfamily Hemibelideinae.The Greater Glider is nocturnal and is a solitary herbivore...
, which restrict their foraging to a single species. The brushtail possum's molar teeth are more rounded than those of the greater glider and the ringtail possum, and cannot cut the leaf tissue of
Eucalyptus foliage as finely as those of these more specialised feeders. However, possums can can crush plant tissue, which enables them to eat fruit or herbs on the forest floor more effectively. The brushtail possums’ caecum is not divided by internal ridges, as in the greater glider and
common ringtail possumThe common ringtail possum is an Australian marsupial. It lives in a variety of habitats and eats a variety of leaves of both native and introduced plants, as well as flowers and fruits. These dietary factors have, over time, aided burgeoning introduced populations in New Zealand...
, and cannot separate coarse and fine particles as efficiently. The brushtail possum cannot selectively retain the fluid and fine particles of an
Eucalyptus diet, so loses much potential nitrogen in its faeces. However, when eating a mixed diet and not
Eucalyptus, brushtail possums obtain enough protein to survive from less food and can still raise their daily intake to meet the extra protein requirement of reproduction, particularly late lactation.
Behaviour
The common brushtail possum is largely arboreal and nocturnal. It has a mostly solitary lifestyle, and individuals maintain spacing between each other through scent-marking, vocalisations and antagonistic encounters. During the daytime, brushtail possums take shelter in dens which may be located in tree hollows, logs, dense undergrowths, caves, burrows of other species and even roof spaces of houses. While they do sometimes share dens, brushtails normally sleep in separate dens. Dens sites appear to be more abundant in New Zealand forests than Australian eucalyptus forests and woodlands. As such, a single brushtail possum in New Zealand can use around 10-15 dens, which is much more than the one to three dens used by single Australian brushtail possums. Competition for dens sites from other brushtail possums, other marsupials, nesting birds and large reptiles, such as
goannaGoanna is the name used to refer to any number of Australian monitor lizards of the genus Varanus, as well as to certain species from Southeast Asia.There are around 30 species of goanna, 25 of which are found in Australia...
s, may contribute to the mortality of brushtail possums in Australia. This is likely another reason why brushtail possum population densities are smaller in Australia than in New Zealand. Nocturnal encounters between adults of either sex are more often mild. They usually avoid direct contact and will peer silently at each other with erect ears. Brushtail possums are among the most vocal marsupials and will communicate with various sounds such as clicks, grunts, hisses, alarm chatters, guttural coughs and screeching. The brushtail possum is normally not aggressive, although it can show aggression when protecting its young, and when shot but not killed.
Reproduction and life history
Common brushtail possums can breed at any time of the year, but breeding tends to peak in spring, from September to November, and in autumn, from March to May, in some areas. Mating is promiscuous and random; some males can sire several young in a season while over half sire none. In one Queensland population, it apparently takes the males one month of consorting with females before they can mate with them. Females have a gestation period of 16-18 days, after which they give birth to single young. A newborn brushtail possum is only 1.5 cm long and weighs only 2 g. As usual for marsupials, the newborn brushtail possum may climb, unaided, through the female’s fur and into the pouch and attach to a teat. The young develops and remains inside the mother’s pouch for another four or five months. When older, the young is left in the den or rides on its mother’s back until it is seven to nine months old. Females reach sexual maturity when they are one year old, and males do so at the end of their second year. Recently, mature female young have a higher survival rate than their males counterparts due to establishing their home ranges closer to their mothers, while males travel farther. In the Orongorongo population, female young have been found to continue to associate with their mothers after weaning, and some will inherit the prime den sites. There is possible competition between mothers and daughters for dens, and daughters may be excluded from a den occupied by the mother. In forests with shortages of den sites, females apparently produce more sons, which do not compete directly for den sites, while in forests with plentiful den sites, female young are greater in number. Brushtail possums can live up to 13 years in the wild.
Relationship with humans
The common brushtail possum is considered a pest in some areas. It is known to cause damage to pine plantations, regenerating forest, flowers, fruit trees and buildings. In addition, it is a known carrier of the highly contagious bovine tuberculosis. Its fur has been considered valuable and has been harvested. However, hunting is currently restricted to Tasmania. Although once hunted extensively for their fur in Australia, the common brushtail possum is now protected. The possum is partially protected in Tasmania and there is an annual hunting season. In addition, landowners in Tasmania can get help controlling the damage done by possums by obtaining Crop Protection Permits. In New Zealand, there are no restrictions on hunting. The population does not seem to be declining, despite thousands of animals being killed each year.
Further reading
- Marsh, K. J., Wallis, I. R., & Foley, W. J. (2003). The effect of inactivating tannins on the intake of Eucalyptus foliage by a specialist Eucalyptus folivore (Pseudocheirus peregrinus) and a generalist herbivore (Trichosurus vulpecula). Australian Journal of Zoology, 51, 41-42.
- Roetman, P.E.J. & Daniels, C.B. (2009): The Possum-Tail Tree: Understanding Possums through Citizen Science. Barbara Hardy Centre for Sustainable Urban Environments, University of South Australia. ISBN 978-0-646-52199-2
External links